Gold has not seen much use as a catalyst due to its relative unreactivity. Although limited, several examples of reactions catalyzed by gold have been disclosed. U.S. Pat. No. 3,449,413 describes a method for the preparation of carboxylic acid salts using an alkaline aqueous medium and a copper oxide/gold mixture. U.S. Pat. Nos. 4,154,762, 4,816,606, and U.S. Pat. No. 3,149,166 all use a gold catalyst for the oxidation of a alcohol to form the corresponding ketone, but all perform the reaction at high temperatures and in the gas phase. U.S. Pat. No. 5,623,090 oxidized hydrocarbon to form an alcohol or ketone at lower temperatures and in liquid phase, but added hydrogen gas is required. U.S. Pat. No. 3,717674 states a gold catalyst may be used for the purification of a terephthalic acid reaction mixture via non-specific oxidation of the by-products therein, but no examples are given.
U.S. Ser. No. 09/245,754 (Druliner, et. al) discloses the use of an improved catalytic process for oxidizing cycloalkanes to form a mixture containing the corresponding alcohol and ketone using a heterogeneous gold catalyst.
The present invention describes methods of utilizing a heterogeneous gold catalyst under mild conditions for the preparation of carboxylic acids, ketones, and diacids. These compounds are useful as synthetic intermediates and in a variety of industries, such as polymer production.